Fixed command to create file user in readme.md

Signed-off-by: Matthias Koller <m.koller@peak-solution.de>
diff --git a/README.md b/README.md
index 8ed5e21..773f612 100644
--- a/README.md
+++ b/README.md
@@ -73,9 +73,10 @@
 asadmin create-auth-realm --classname com.sun.enterprise.security.auth.realm.file.FileRealm --property file=${com.sun.aas.instanceRoot}/config/mdm-keyfile:jaas-context=MDMRealm:assign-groups=Guest MDMRealm
 ```
 
-To be able to login you need to explicitly add users to the `MDMRealm`
+To be able to login you need to explicitly add users to the `MDMRealm`. 
+Here we add the user `MdmUser`
 ```
-asadmin create-file-user --authrealmname --groups MDMRealm Admin:DescriptiveDataAuthor:Guest
+asadmin create-file-user --authrealmname MDMRealm --groups Admin:DescriptiveDataAuthor:Guest MdmUser
 ```
 
 Currently three roles are supported by openMDM, adapt the users according to your needs